The specific aims are to identify, purify and characterize the sperm-specific antigens involved in human immunologic infertility. To explore the antigenic contsituency of sperm we propose to use the SDS-PAGE/protein blot radioimmunobinding method as a major tool. Sera and genital tract secretions of infertile men and women, antisperm antesera produced in animals and monoclonal antibodies from hybridomas, all characterized as to defined biologic effects on sperm cells, will be used in the blot method to identify the sperm immunogens. Identified antigens will be purified by antibody affinity columns and conventional means. After purification the antigens will be characterized biochemically as to their chemical nature and immunocytochemically as to site of origin on the sperm cell and during spermatogenesis. Having purified and characterized antigens will allow: 1) the development of quantitative and qualitative immunoassays to evaluate the presence of antisperm antibodies in the sera and genital tract secretions of infertile patients and 2) a basis for preparation and evaluation of different membrane antigens as potential contraceptive vaccines.